1. Field of the Invention
This invention relates to a semiconductor device comprising a circuit substrate with inspection connection pads and a manufacturing method thereof.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication No. 2004-207306 discloses a semiconductor device in which a semiconductor construct having a semiconductor substrate and a plurality of external connection electrodes provided on the semiconductor substrate is installed on a substrate having a planar size larger than that of the semiconductor construct. The semiconductor construct described in this patent document further has external connection columnar electrodes which are connected to connection pads of an integrated circuit unit formed on the surface of the semiconductor substrate and which are to be connected to an external circuit or device, and a sealing film filled between the columnar electrodes. The semiconductor construct is installed on the substrate, and an insulating layer is provided on the substrate around the semiconductor construct. An upper insulating film is provided on the semiconductor construct and the insulating layer. An upper wiring substrate including upper wiring lines electrically connected to the columnar electrodes of the semiconductor construct is provided on the upper insulating film. Solder balls are provided on connection pad portions of the upper wiring lines.
In the semiconductor device described in the above-mentioned patent document, the semiconductor construct has the columnar electrodes and the sealing film filled between the columnar electrodes, which allows the semiconductor construct and the upper wiring substrate to be securely joined together and also allows the columnar electrodes and the upper wiring lines to be electrically connected together in a firm and reliable way.
As the semiconductor construct of the conventional semiconductor device described above is structured to be sealed by the substrate, the insulating layer disposed therearound and the upper wiring substrate disposed thereover, it is not possible to inspect this device until the upper wiring lines having the connection pad portions are formed, that is, until the device is completed. There is thus a disadvantage that it is difficult to repair defective products and that the yield ratio aggravates.
Moreover, the conventional semiconductor device has a structure in which the connection pad portions of the upper wiring lines to be connected to the external circuit or device are only exposed and no connection pads exclusive to an inspection are exposed, so that it is absolutely impossible to inspect the integrated circuit unit contained in the semiconductor construct incorporated in the semiconductor device. In addition, when another electronic component such as a semiconductor construct is further installed on the upper wiring substrate, the connection pad portions of the upper wiring lines are covered with this electronic component, so that it is not at all possible to conduct an inspection when this semiconductor construct is installed.